Shape-shifting structured lattices via multimaterial 4D printing

Area of Science:

• Materials Science
• Mechanical Engineering
• Additive Manufacturing

Background:

• Designing shape-morphing materials is complex due to challenges in controlling the metric tensor in space and time.
• Existing methods struggle with precise control over material properties and geometric configurations.

Purpose of the Study:

• To develop a novel method for creating shape-morphing structured materials with precise control over their transformations.
• To overcome the limitations in designing and fabricating complex, programmable shape-shifting materials.

Main Methods:

• Utilized a combination of multiple materials, geometry, and 4-dimensional (4D) printing.
• Developed printable inks with elastomeric matrices and anisotropic fillers for tunable elastic modulus and thermal expansion.
• Designed lattices with curved bilayer ribs, programmed for local control over the metric tensor and extrinsic curvature.

Main Results:

• Successfully created structured heterogeneous lattices capable of complex 3D shape changes in response to temperature.
• Demonstrated the ability to programmatically control the metric tensor and extrinsic curvature using multiplexed bilayer ribs.
• Printed functional prototypes, including frequency-shifting antennae and a human face, showcasing geometric complexity and functionality.

Conclusions:

• The inverse geometric design and multimaterial 4D printing approach enables unprecedented control over shape-morphing materials.
• This method is extendable to various stimuli-responsive materials and cell designs for scalable, reversible shape-shifting structures.
• The developed technique offers a powerful platform for creating advanced functional materials with complex, programmable form changes.